1 /*
   2  * Copyright (c) 2003, 2016, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "jvmtifiles/jvmtiEnv.hpp"
  27 #include "prims/jvmtiExport.hpp"
  28 #include "prims/jvmtiManageCapabilities.hpp"
  29 static const jint CAPA_SIZE = (JVMTI_INTERNAL_CAPABILITY_COUNT + 7) / 8;
  30 
  31   // capabilities which are always potentially available
  32 jvmtiCapabilities JvmtiManageCapabilities::always_capabilities;
  33 
  34   // capabilities which are potentially available during OnLoad
  35 jvmtiCapabilities JvmtiManageCapabilities::onload_capabilities;
  36 
  37   // capabilities which are always potentially available
  38   // but to only one environment
  39 jvmtiCapabilities JvmtiManageCapabilities::always_solo_capabilities;
  40 
  41   // capabilities which are potentially available during OnLoad
  42   // but to only one environment
  43 jvmtiCapabilities JvmtiManageCapabilities::onload_solo_capabilities;
  44 
  45   // remaining capabilities which are always potentially available
  46   // but to only one environment
  47 jvmtiCapabilities JvmtiManageCapabilities::always_solo_remaining_capabilities;
  48 
  49   // remaining capabilities which are potentially available during OnLoad
  50   // but to only one environment
  51 jvmtiCapabilities JvmtiManageCapabilities::onload_solo_remaining_capabilities;
  52 
  53   // all capabilities ever acquired
  54 jvmtiCapabilities JvmtiManageCapabilities::acquired_capabilities;
  55 
  56 void JvmtiManageCapabilities::initialize() {
  57   always_capabilities = init_always_capabilities();
  58   if (JvmtiEnv::get_phase() != JVMTI_PHASE_ONLOAD) {
  59     recompute_always_capabilities();
  60   }
  61   onload_capabilities = init_onload_capabilities();
  62   always_solo_capabilities = init_always_solo_capabilities();
  63   onload_solo_capabilities = init_onload_solo_capabilities();
  64   always_solo_remaining_capabilities = init_always_solo_capabilities();
  65   onload_solo_remaining_capabilities = init_onload_solo_capabilities();
  66   memset(&acquired_capabilities, 0, sizeof(acquired_capabilities));
  67 }
  68 
  69 // if the capability sets are initialized in the onload phase then
  70 // it happens before class data sharing (CDS) is initialized. If it
  71 // turns out that CDS gets disabled then we must adjust the always
  72 // capabilities. To ensure a consistent view of the capabililties
  73 // anything we add here should already be in the onload set.
  74 void JvmtiManageCapabilities::recompute_always_capabilities() {
  75   if (!UseSharedSpaces) {
  76     jvmtiCapabilities jc = always_capabilities;
  77     jc.can_generate_all_class_hook_events = 1;
  78     always_capabilities = jc;
  79   }
  80 }
  81 
  82 
  83 // corresponding init functions
  84 jvmtiCapabilities JvmtiManageCapabilities::init_always_capabilities() {
  85   jvmtiCapabilities jc;
  86 
  87   memset(&jc, 0, sizeof(jc));
  88   jc.can_get_bytecodes = 1;
  89   jc.can_signal_thread = 1;
  90   jc.can_get_source_file_name = 1;
  91   jc.can_get_line_numbers = 1;
  92   jc.can_get_synthetic_attribute = 1;
  93   jc.can_get_monitor_info = 1;
  94   jc.can_get_constant_pool = 1;
  95   jc.can_generate_monitor_events = 1;
  96   jc.can_generate_garbage_collection_events = 1;
  97   jc.can_generate_compiled_method_load_events = 1;
  98   jc.can_generate_native_method_bind_events = 1;
  99   jc.can_generate_vm_object_alloc_events = 1;
 100   if (os::is_thread_cpu_time_supported()) {
 101     jc.can_get_current_thread_cpu_time = 1;
 102     jc.can_get_thread_cpu_time = 1;
 103   }
 104   jc.can_redefine_classes = 1;
 105   jc.can_redefine_any_class = 1;
 106   jc.can_retransform_classes = 1;
 107   jc.can_retransform_any_class = 1;
 108   jc.can_set_native_method_prefix = 1;
 109   jc.can_tag_objects = 1;
 110   jc.can_generate_object_free_events = 1;
 111   jc.can_generate_resource_exhaustion_heap_events = 1;
 112   jc.can_generate_resource_exhaustion_threads_events = 1;
 113   return jc;
 114 }
 115 
 116 jvmtiCapabilities JvmtiManageCapabilities::init_onload_capabilities() {
 117   jvmtiCapabilities jc;
 118 
 119   memset(&jc, 0, sizeof(jc));
 120 #ifndef ZERO
 121   jc.can_pop_frame = 1;
 122   jc.can_force_early_return = 1;
 123 #endif // !ZERO
 124   jc.can_get_source_debug_extension = 1;
 125   jc.can_access_local_variables = 1;
 126   jc.can_maintain_original_method_order = 1;
 127   jc.can_generate_all_class_hook_events = 1;
 128   jc.can_generate_single_step_events = 1;
 129   jc.can_generate_exception_events = 1;
 130   jc.can_generate_frame_pop_events = 1;
 131   jc.can_generate_method_entry_events = 1;
 132   jc.can_generate_method_exit_events = 1;
 133   jc.can_get_owned_monitor_info = 1;
 134   jc.can_get_owned_monitor_stack_depth_info = 1;
 135   jc.can_get_current_contended_monitor = 1;
 136   jc.can_generate_early_vmstart = 1;
 137   return jc;
 138 }
 139 
 140 
 141 jvmtiCapabilities JvmtiManageCapabilities::init_always_solo_capabilities() {
 142   jvmtiCapabilities jc;
 143 
 144   memset(&jc, 0, sizeof(jc));
 145   jc.can_suspend = 1;
 146   return jc;
 147 }
 148 
 149 
 150 jvmtiCapabilities JvmtiManageCapabilities::init_onload_solo_capabilities() {
 151   jvmtiCapabilities jc;
 152 
 153   memset(&jc, 0, sizeof(jc));
 154   jc.can_generate_field_modification_events = 1;
 155   jc.can_generate_field_access_events = 1;
 156   jc.can_generate_breakpoint_events = 1;
 157   return jc;
 158 }
 159 
 160 
 161 jvmtiCapabilities *JvmtiManageCapabilities::either(const jvmtiCapabilities *a, const jvmtiCapabilities *b,
 162                                                    jvmtiCapabilities *result) {
 163   char *ap = (char *)a;
 164   char *bp = (char *)b;
 165   char *resultp = (char *)result;
 166 
 167   for (int i = 0; i < CAPA_SIZE; ++i) {
 168     *resultp++ = *ap++ | *bp++;
 169   }
 170 
 171   return result;
 172 }
 173 
 174 
 175 jvmtiCapabilities *JvmtiManageCapabilities::both(const jvmtiCapabilities *a, const jvmtiCapabilities *b,
 176                                                     jvmtiCapabilities *result) {
 177   char *ap = (char *)a;
 178   char *bp = (char *)b;
 179   char *resultp = (char *)result;
 180 
 181   for (int i = 0; i < CAPA_SIZE; ++i) {
 182     *resultp++ = *ap++ & *bp++;
 183   }
 184 
 185   return result;
 186 }
 187 
 188 
 189 jvmtiCapabilities *JvmtiManageCapabilities::exclude(const jvmtiCapabilities *a, const jvmtiCapabilities *b,
 190                                                     jvmtiCapabilities *result) {
 191   char *ap = (char *)a;
 192   char *bp = (char *)b;
 193   char *resultp = (char *)result;
 194 
 195   for (int i = 0; i < CAPA_SIZE; ++i) {
 196     *resultp++ = *ap++ & ~*bp++;
 197   }
 198 
 199   return result;
 200 }
 201 
 202 
 203 bool JvmtiManageCapabilities::has_some(const jvmtiCapabilities *a) {
 204   char *ap = (char *)a;
 205 
 206   for (int i = 0; i < CAPA_SIZE; ++i) {
 207     if (*ap++ != 0) {
 208       return true;
 209     }
 210   }
 211 
 212   return false;
 213 }
 214 
 215 
 216 void JvmtiManageCapabilities::copy_capabilities(const jvmtiCapabilities *from, jvmtiCapabilities *to) {
 217   char *ap = (char *)from;
 218   char *resultp = (char *)to;
 219 
 220   for (int i = 0; i < CAPA_SIZE; ++i) {
 221     *resultp++ = *ap++;
 222   }
 223 }
 224 
 225 
 226 void JvmtiManageCapabilities::get_potential_capabilities(const jvmtiCapabilities *current,
 227                                                          const jvmtiCapabilities *prohibited,
 228                                                          jvmtiCapabilities *result) {
 229   // exclude prohibited capabilities, must be before adding current
 230   exclude(&always_capabilities, prohibited, result);
 231 
 232   // must include current since it may possess solo capabilities and now prohibited
 233   either(result, current, result);
 234 
 235   // add other remaining
 236   either(result, &always_solo_remaining_capabilities, result);
 237 
 238   // if this is during OnLoad more capabilities are available
 239   if (JvmtiEnv::get_phase() == JVMTI_PHASE_ONLOAD) {
 240     either(result, &onload_capabilities, result);
 241     either(result, &onload_solo_remaining_capabilities, result);
 242   }
 243 }
 244 
 245 jvmtiError JvmtiManageCapabilities::add_capabilities(const jvmtiCapabilities *current,
 246                                                      const jvmtiCapabilities *prohibited,
 247                                                      const jvmtiCapabilities *desired,
 248                                                      jvmtiCapabilities *result) {
 249   // check that the capabilities being added are potential capabilities
 250   jvmtiCapabilities temp;
 251   get_potential_capabilities(current, prohibited, &temp);
 252   if (has_some(exclude(desired, &temp, &temp))) {
 253     return JVMTI_ERROR_NOT_AVAILABLE;
 254   }
 255 
 256   // add to the set of ever acquired capabilities
 257   either(&acquired_capabilities, desired, &acquired_capabilities);
 258 
 259   // onload capabilities that got added are now permanent - so, also remove from onload
 260   both(&onload_capabilities, desired, &temp);
 261   either(&always_capabilities, &temp, &always_capabilities);
 262   exclude(&onload_capabilities, &temp, &onload_capabilities);
 263 
 264   // same for solo capabilities (transferred capabilities in the remaining sets handled as part of standard grab - below)
 265   both(&onload_solo_capabilities, desired, &temp);
 266   either(&always_solo_capabilities, &temp, &always_solo_capabilities);
 267   exclude(&onload_solo_capabilities, &temp, &onload_solo_capabilities);
 268 
 269   // remove solo capabilities that are now taken
 270   exclude(&always_solo_remaining_capabilities, desired, &always_solo_remaining_capabilities);
 271   exclude(&onload_solo_remaining_capabilities, desired, &onload_solo_remaining_capabilities);
 272 
 273   // return the result
 274   either(current, desired, result);
 275 
 276   update();
 277 
 278   return JVMTI_ERROR_NONE;
 279 }
 280 
 281 
 282 void JvmtiManageCapabilities::relinquish_capabilities(const jvmtiCapabilities *current,
 283                                                       const jvmtiCapabilities *unwanted,
 284                                                       jvmtiCapabilities *result) {
 285   jvmtiCapabilities to_trash;
 286   jvmtiCapabilities temp;
 287 
 288   // can't give up what you don't have
 289   both(current, unwanted, &to_trash);
 290 
 291   // restore solo capabilities but only those that belong
 292   either(&always_solo_remaining_capabilities, both(&always_solo_capabilities, &to_trash, &temp),
 293          &always_solo_remaining_capabilities);
 294   either(&onload_solo_remaining_capabilities, both(&onload_solo_capabilities, &to_trash, &temp),
 295          &onload_solo_remaining_capabilities);
 296 
 297   update();
 298 
 299   // return the result
 300   exclude(current, unwanted, result);
 301 }
 302 
 303 
 304 void JvmtiManageCapabilities::update() {
 305   jvmtiCapabilities avail;
 306 
 307   // all capabilities
 308   either(&always_capabilities, &always_solo_capabilities, &avail);
 309 
 310   bool interp_events =
 311     avail.can_generate_field_access_events ||
 312     avail.can_generate_field_modification_events ||
 313     avail.can_generate_single_step_events ||
 314     avail.can_generate_frame_pop_events ||
 315     avail.can_generate_method_entry_events ||
 316     avail.can_generate_method_exit_events;
 317 #ifdef ZERO
 318   bool enter_all_methods =
 319     interp_events ||
 320     avail.can_generate_breakpoint_events;
 321   if (enter_all_methods) {
 322     // Disable these when tracking the bytecodes
 323     UseFastEmptyMethods = false;
 324     UseFastAccessorMethods = false;
 325   }
 326 #endif // ZERO
 327 
 328   if (avail.can_generate_breakpoint_events) {
 329     RewriteFrequentPairs = false;
 330   }
 331 
 332   // If can_redefine_classes is enabled in the onload phase then we know that the
 333   // dependency information recorded by the compiler is complete.
 334   if ((avail.can_redefine_classes || avail.can_retransform_classes) &&
 335       JvmtiEnv::get_phase() == JVMTI_PHASE_ONLOAD) {
 336     JvmtiExport::set_all_dependencies_are_recorded(true);
 337   }
 338 
 339   JvmtiExport::set_can_get_source_debug_extension(avail.can_get_source_debug_extension);
 340   JvmtiExport::set_can_maintain_original_method_order(avail.can_maintain_original_method_order);
 341   JvmtiExport::set_can_post_interpreter_events(interp_events);
 342   JvmtiExport::set_can_hotswap_or_post_breakpoint(
 343     avail.can_generate_breakpoint_events ||
 344     avail.can_redefine_classes ||
 345     avail.can_retransform_classes);
 346   JvmtiExport::set_can_modify_any_class(
 347     avail.can_generate_breakpoint_events ||
 348     avail.can_generate_all_class_hook_events);
 349   JvmtiExport::set_can_walk_any_space(
 350     avail.can_tag_objects);   // disable sharing in onload phase
 351   // This controls whether the compilers keep extra locals live to
 352   // improve the debugging experience so only set them if the selected
 353   // capabilities look like a debugger.
 354   JvmtiExport::set_can_access_local_variables(
 355     avail.can_access_local_variables ||
 356     avail.can_generate_breakpoint_events ||
 357     avail.can_generate_frame_pop_events);
 358   JvmtiExport::set_can_post_on_exceptions(
 359     avail.can_generate_exception_events ||
 360     avail.can_generate_frame_pop_events ||
 361     avail.can_generate_method_exit_events);
 362   JvmtiExport::set_can_post_breakpoint(avail.can_generate_breakpoint_events);
 363   JvmtiExport::set_can_post_field_access(avail.can_generate_field_access_events);
 364   JvmtiExport::set_can_post_field_modification(avail.can_generate_field_modification_events);
 365   JvmtiExport::set_can_post_method_entry(avail.can_generate_method_entry_events);
 366   JvmtiExport::set_can_post_method_exit(avail.can_generate_method_exit_events ||
 367                                         avail.can_generate_frame_pop_events);
 368   JvmtiExport::set_can_pop_frame(avail.can_pop_frame);
 369   JvmtiExport::set_can_force_early_return(avail.can_force_early_return);
 370   JvmtiExport::set_should_clean_up_heap_objects(avail.can_generate_breakpoint_events);
 371 }
 372 
 373 #ifndef PRODUCT
 374 
 375 void JvmtiManageCapabilities:: print(const jvmtiCapabilities* cap) {
 376   tty->print_cr("----- capabilities -----");
 377   if (cap->can_tag_objects)
 378     tty->print_cr("can_tag_objects");
 379   if (cap->can_generate_field_modification_events)
 380     tty->print_cr("can_generate_field_modification_events");
 381   if (cap->can_generate_field_access_events)
 382     tty->print_cr("can_generate_field_access_events");
 383   if (cap->can_get_bytecodes)
 384     tty->print_cr("can_get_bytecodes");
 385   if (cap->can_get_synthetic_attribute)
 386     tty->print_cr("can_get_synthetic_attribute");
 387   if (cap->can_get_owned_monitor_info)
 388     tty->print_cr("can_get_owned_monitor_info");
 389   if (cap->can_get_current_contended_monitor)
 390     tty->print_cr("can_get_current_contended_monitor");
 391   if (cap->can_get_monitor_info)
 392     tty->print_cr("can_get_monitor_info");
 393   if (cap->can_get_constant_pool)
 394     tty->print_cr("can_get_constant_pool");
 395   if (cap->can_pop_frame)
 396     tty->print_cr("can_pop_frame");
 397   if (cap->can_force_early_return)
 398     tty->print_cr("can_force_early_return");
 399   if (cap->can_redefine_classes)
 400     tty->print_cr("can_redefine_classes");
 401   if (cap->can_retransform_classes)
 402     tty->print_cr("can_retransform_classes");
 403   if (cap->can_signal_thread)
 404     tty->print_cr("can_signal_thread");
 405   if (cap->can_get_source_file_name)
 406     tty->print_cr("can_get_source_file_name");
 407   if (cap->can_get_line_numbers)
 408     tty->print_cr("can_get_line_numbers");
 409   if (cap->can_get_source_debug_extension)
 410     tty->print_cr("can_get_source_debug_extension");
 411   if (cap->can_access_local_variables)
 412     tty->print_cr("can_access_local_variables");
 413   if (cap->can_maintain_original_method_order)
 414     tty->print_cr("can_maintain_original_method_order");
 415   if (cap->can_generate_single_step_events)
 416     tty->print_cr("can_generate_single_step_events");
 417   if (cap->can_generate_exception_events)
 418     tty->print_cr("can_generate_exception_events");
 419   if (cap->can_generate_frame_pop_events)
 420     tty->print_cr("can_generate_frame_pop_events");
 421   if (cap->can_generate_breakpoint_events)
 422     tty->print_cr("can_generate_breakpoint_events");
 423   if (cap->can_suspend)
 424     tty->print_cr("can_suspend");
 425   if (cap->can_redefine_any_class )
 426     tty->print_cr("can_redefine_any_class");
 427   if (cap->can_retransform_any_class )
 428     tty->print_cr("can_retransform_any_class");
 429   if (cap->can_get_current_thread_cpu_time)
 430     tty->print_cr("can_get_current_thread_cpu_time");
 431   if (cap->can_get_thread_cpu_time)
 432     tty->print_cr("can_get_thread_cpu_time");
 433   if (cap->can_generate_method_entry_events)
 434     tty->print_cr("can_generate_method_entry_events");
 435   if (cap->can_generate_method_exit_events)
 436     tty->print_cr("can_generate_method_exit_events");
 437   if (cap->can_generate_all_class_hook_events)
 438     tty->print_cr("can_generate_all_class_hook_events");
 439   if (cap->can_generate_compiled_method_load_events)
 440     tty->print_cr("can_generate_compiled_method_load_events");
 441   if (cap->can_generate_monitor_events)
 442     tty->print_cr("can_generate_monitor_events");
 443   if (cap->can_generate_vm_object_alloc_events)
 444     tty->print_cr("can_generate_vm_object_alloc_events");
 445   if (cap->can_generate_native_method_bind_events)
 446     tty->print_cr("can_generate_native_method_bind_events");
 447   if (cap->can_generate_garbage_collection_events)
 448     tty->print_cr("can_generate_garbage_collection_events");
 449   if (cap->can_generate_object_free_events)
 450     tty->print_cr("can_generate_object_free_events");
 451   if (cap->can_generate_resource_exhaustion_heap_events)
 452     tty->print_cr("can_generate_resource_exhaustion_heap_events");
 453   if (cap->can_generate_resource_exhaustion_threads_events)
 454     tty->print_cr("can_generate_resource_exhaustion_threads_events");
 455   if (cap->can_generate_early_vmstart)
 456     tty->print_cr("can_generate_early_vmstart");
 457 }
 458 
 459 #endif